HARARE – A Cypriot investor signed a $4.2-billion deal on Thursday to develop a platinum mine and refinery in Zimbabwe, an investment that President Emmerson Mnangagwa said showed the country was "open for business".

Signing the agreement with Cyprus-based Karo Resources, Mines Minister Winston Chitando said work would start in July, with the first output of platinum group metals expected in 2020, aiming to reach 1.4 million ounces annually within three years.

Located in the Mhondoro-Ngezi platinum belt, west of Harare, where Impala Platinum Holdings has operations, the project will include a coal mine and power station to produce electricity for the smelter, and should employ 15,000 people when fully implemented, according to Karo head Loucas Pouroulis.

Keen to revive the mining sector after years of reticence by foreign investors during Robert Mugabe's rule, President Mnangagwa said the deal was a signal things had changed since his ascendency after Mugabe's ousting in November.

"Zimbabwe is open for business and whoever stands in the way, hurting business in this country, will fall. It is not business as usual anymore, things have to change," Mnangagwa said at the signing ceremony.

The project was first mooted six years ago but had been held back by government red tape and "other unnamed vested interests, which are corrupt interests," he said.

Mines Minister Chitando added: "This is the largest investment structure in the country's mining industry in Zimbabwe. The landscape of Zimbabwe's mining industry will never be the same."

Cyprus-born Pouroulis spent his early career with industry giant Anglo American in South Africa, branching out on his own to establish niche operators such as Petra Diamonds, Eland Platinum and Tharisa Minerals, according to his profile on Tharisa's website.

He did not give the source of funding for the venture.

Zimbabwe holds the world's second-largest platinum deposits after neighbour South Africa but foreign investment had stalled during the latter years of Mugabe's reign.

On Monday, Mnangagwa's government amended the Mugabe-era Indigenisation and Economic Empowerment Act, which aimed to increase black Zimbabweans' ownership of mines by preventing foreign entities holding majority stakes.

The revised law removed that stipulation for most types of mining, but not diamond and platinum mines.

Chitando said Karo Resources was expected to comply with the empowerment law by giving up majority ownership in the project. He did not elaborate.